Inter-deck soot blower



Oct. 16, 1956 R, s. COOPER ET AL 2,766,969

INTER-DECK SOOT BLOWER Filed April 5, 1952 2 Sheets-Sheet 2 IN V EN TOR. fl /0mm A e/k BY 9 74" 5 Coyaer 4 TTOR/VE) United States Patent O INTER-DECK SOOT BLOWER Roland S. Cooper, River Forest, 111., and Benjamin S. Kelley, Atlanta, -Ga., assignors to The Air Preheater Corporation, New York, N. Y.

Application April 5, 1952, Serial No. 280,732

8 Claims. (Cl. 257-1) This invention relates to heat transfer apparatus of the regenerative type and more particularly to an improved means for removing soot and other deposited matter from the heat exchange surfaces in the rotor of an air preheater.

In a regenerative air preheater, metallic heat transfer plates which are carried in compartments of a rotor ab sorb heat winch passes through the gas side of the preheater. On rotation of the rotor, said plates yield their heat to cool air which flows in countercurrent relation through the air side of the preheater. Fly ash and soot which are carried by the hot furnace gases tend to deposit on the plates within the compartments thereby obstructing flow of the gases and necessitating frequent cleaning.

It is therefore an object of this invention to provide an improved device which will eifectively remove the deposits of soot and fly ash from the heat exchanger plates of a rotary air preheater.

It is a further object of our invention to provide for a cleaning device which rotates between decks of heat exchange elements so as to more effectively clean all surfaces above and below the cleaning device.

The invention will best be understood upon consideration of the following detailed description of an illustrative embodiment thereof when read in conjunction with the accompanying drawings in which: 7

Figure 1 is a sectional elevation of a rotary air preheater showing the interdeck soot blowers in position.

Figure 2 is a sectional side elevation on a larger scale, taken through the rotor post.

Figure 3 is a large scale plan view partly in section showing the connection of the soot blower pipes to the steam supply.

-In Figure 1 or" the drawings the numeral designates the cylindrical shell of a rotor that is divided into sector shaped compartments by radial partitions connecting it with the rotor post 12 which is driven by a motor through reduction gearing 13 to turn the rotor slowly about its axis. The rotor compartments contain regenerative heat transfer material in the form of metallic plates which first absorb heat from hot gases entering the preheater through a duct 15 from a boiler or other source to be discharged after passing over the heat transfer plates through an outlet duct 16 to which an induced draft fan (not shown) is connected. As the rotor turns slowly about its axis, the heated plates are moved into the stream of air admitted through the duct 17 to which a forced draft fan (not shown) is connected. After passing over the heated plates and absorbing heat therefrom the stream of air is conveyed to the boiler furnace or other place of use through duct 18. A housing 20 enclosing the rotor 10 is provided at either end opposite the latter with end or sector plates 21 which are apertured at 22 and 23 to permit streams of gas and air to enter and leave the preheater.

The mass of heat transfer surface consisting of the metal plates carried by the rotor 10 is in accordance with the invention divided into an upper and a lower layer 24, 25 respectively or two decks separated by an inter- 2 deck space 26 in which is mounted a pressure jet fluidcleaning device designated as a Whole by 27.

The cleaners or soot blowers of the present invention have been designed with the object of applying them to existing air preheaters with a minimum of alteration. Similar cleaners could readily be adapted to new'construc= tion.

In Figure 2 the cleaning device 27 has been shown as applied to an existing preheater in which 30 indicates the lower trunnion terminating in the guide bearing 31. The lower trunnion is bolted 'as at 32 to the rotor post 12. The rotor is turned by conventional means connected to an upper support trunnion, the upper support trunnion is in turn joined to the upper portion of the rotor post 33 by bolts through openings '34. A supply pipe 35 leads to the rotatable joint 36 which is connected via pipe 37 to the funnel shaped member 38. Said member '38 serves as a housing for an adniission port block 40 which contains an arcuate opening 41. Connected to the admission port block 40 by means of rod 42 is a locking member 43, This member is manually rotatable and serves to lock the admission port block 40 in a single position. In this Way, steam or other cleaning fluid which is supplied through pipe 35 can be directed to either the air side or the gas side of the rotor by shifting port 41 from one side to the other. Rod 42 is connected to the admission port block 49 through a universal joint 44.

Located within the rotor post 12 and joined to either side of its two dividing plates 59 and 51 are two semicylindrical forgings 52 and 53. Each of these forgings contains three passageways 54 which extend parallel to the axis of the rotor post. These passageways are selec tively open or closed at their bottom ends to the arcuate port 41 in the admission port block 40. The upper portion of each passageway has two openings 57, 58 each of which extends radially toward an opening 39 in the rotor post. Extending through each opening 61 in the forgings 52 and 53 are soot blower pipes 63. Each ofsuch pipes extends radially through the opening 61 in the rotor post and through openings 64 (Fig. 2) in the rotor shell 10, terminating in the annular space 65 between the rotor shell and the rotor housing 20.

Separating each soot blower pipe into a radially inner and outer portion is a rotary joint 67 which makes the outer portion rotatable with respect to the inner portion. Each soot blower pipe is closed at its distal end and has a series of emission ports 68 located along said pipe.

Welded or otherwise joined to the end of each blower pipe 61 in the space 65 are a plurality of pins 71 which may form a star-wheel. On rotation of the preheater rotor 10 and soot blower pipes 61 carried thereby, each of the pins 70 successively contacts one of a plurality of pins 71 which extends inwardly from the rotor housing 43, thus rotating the outer portion of each soot blower pipe. The frequency of rotation of the soot blower pipes is dependent upon the relative number of pins 70 and 71.

In operation, the admission port block 40 is rotated and locked into position by the admission port locking device 43 with port 41 registering with the air at the gas side. Steam or pressurized air for soot blowing purposes is admitted via supply pipe 35 and pipe 37 to the chamber inside conical member 38. There the steam is supplied successively to the rotary ports 54 by the stationary arcuate port 41.

The rotor post 10 with its forgings 52 and 53 contains parallel passageways 54 which rotate with respect to the admission port block 49. Consequently, only when port 41 registers with one of the passageways 54 wiil there be a supply of steam to the corresponding pair of soot blowing pipes 61.

When steam is supplied to one of the passageways 54 and its corresponding two blower pipes 61, there is an emission o f steam through the ports 68 of the pipe. As

heat exchange elements.-

'What we claim is: V V a I 1. In a regenerative typeof air preheater having a housing formed with parallel passages for the counter current flow of hot gases and air; a rotor in said housing, said rotor being divided into upper and lower layers of heat exchange elements supported by a central rotor post; and aplurality of pipes extending radially from the rotor post between the layers of heat exchange elements for the supply of cleaning fluid thereto. 2. In a regenerative type air preheater having a housing formed with parallel passagesfor the countercurrent flow of hot gases and air; a rotor in said housing, said rotor being divided into an upper and lower layer of heat exchange elements supported'from a centralrotor post;

' aplurality of pipes extending radially from the rotor post through the space between layers of heat exchange elements; and means for supplying washing fluid to the radially extending pipes during rotation of the rotor.

3. In a regenerative type of air preheater having a housing formed with parallel passages for the countercurrent flow of hot gases and air; a rotor in said housing,

said rotor being divided into upper and lower layers of heat exchange elements, each of which are supported by a central rotorpost to provide a spacev therebetween; a plurality of ported pipes extending radially from the rotor post into the space between upper and lower layers of-heat exchange elements; and means allowing for a free' rotation of the outer end portion of each radially extending pipe. I

' 4. In a regenerative type of air preheater having a housing formed with parallel passages for the countercurrent flow of hot gases and air; a rotor in said housing, said, rotor being separated into an upper and lower layer of heat exchange elements supported from a central rotor post; a plurality of ported blower pipes extending radially from the'rotor post through the space between layers of heat exchange elements; means for each pipe which allows for a free rotation thereof; and means to supply fluid to the radially extending pipes during rotation of the rotor. I

5. In a rotary regenerative type air preheater having a housing formed with parallel passages for the countercurrent flow ofhot gases and air; an inner rotor shell concentric with said housing carrying an upper and a lower layer of heat exchange elements supported from a central rotor post; a plurality of ported blower pipes extending radially from the rotor post into the space bea 4 a. tween said rotor shell and rotor housing; and means permitting rotation of each blower pipe about its longitudinal axis so as to effectively supply a cleaning fluid to the heating elements positioned both above and below said blower pipes.

6. In a rotary regenerative type air preheater having a housing formed with parallel passages for the countercurrent flow of hot gases and air therethrough; a rotor shell concentrally positioned within said housing carrying spaced upper and lower layers of heat exchange elements supported from an axial rotor post; a plurality of circumferentially positioned longitudinally ported blower pipes extending radially outward from said rotor post into the space between said upper and, lower layers ofheat exchange elements; rotatable joints in each blower pipe permitting rotation of the outward portionthereof and valving means in said rotor post supplying fluid to the radially extending pipes during rotation of the rotor.

7. A rotary regenerative air preheater having a housing formed with parallel passages for the countercurrent flow of hot gases and air therethrough; a rotor shell concentric within said housing carrying spaced upperf and lower layers of heating elements; a plurality of ported blower pipes extending radially outward from the rotor post through circumferentially spaced openings in the' rotor shell and terminating in the annular space between the concentric rotor shell and rotor housing; rotatable joints in each blower pipe permitting rotation of the outer portion thereof; and means positioned in said annularspace for'rotating each blower pipe about its longitudinal axis.

8. An air preheater according to claim 7 wherein the means rotating each blower pipe about its axis comprises a star wheelatthe end of each blower pipe cooperating with pin means projecting inwardly from the rotor housing a References Cited in the file of this patent v UNITED STATES PATENTS 1,026,060 Sprenger May 14, 1912 1,441,431 Kirgan Jan. 9, 1923 1,644,995 Grace Oct. 11, 1927 1,858,508 Kignell et al May 17, 1932 2,058,062 Cowles Oct. 20, 1936 2,234,222 Bearer Mar. 11, 1941' 2,289,700 Eiben July 14, 1942 2,350,202 Thomas May 30, 1944 2,379,506 Yerrick et al. July 3, 1945 FOREIGN PATENTS.

156,533 Germany Aug. 26, 1903 503,857 Great Britain Apr. 17, 1939 

